[Question] What should I upgrade first?

Noob guitar player here.

I’ve already asked a question about humm from pedals (or amp).

Two years ago I bought an Epiphone Les Paul Special II-2E which included an Epiphone Electar 10 practice amp, bag, tuner etc.

I’ve really put in the practice and reckon that I’m now up to around Grade 5 standard.

So the questoin is, what do I upgrade next? Guitar or practice amp? Or hold off until I’m substantially better?

I have a Hartke 120W bass amp that I can use but it is a bass amp. I don’t think I can use pedals with the Epiphone amp (see other recent post) but I don’t have any crunch or overdive with the bass amp. So an amp would in some ways make more sense.

But then the sound is only as good as the instrument (and the person playing it). Would a better guitar make more sense? I feel that the action is really high on the Les Paul although I can’t go any lower due to the amount of fret buzz. I often wonder whether I would find it easier to play if I bought a better guitar that would likely have less fret buzz even with a lower action.

Or perhaps I just keep with what I’ve got.

Thanks